Biological value (BV) describes how much of our food’s protein in incorporated in your body’s protein synthesis. There are 9 essential amino acids (smallest unit of protein) meaning that our body can’t synthesize them. A complete protein source contains all of those 9 amino acids. As most animal products are considered complete proteins some vegetarians/vegans might find it difficult to get their amino acids. But there are certain vegetarian food combinations, which lead to a complete protein when eaten together. One good example is eggs plus (sweet) potato.